After last featuring in the Premier League with Sunderland two years ago, Alonso revealed his delight at returning to play in England.

“I’m very happy. It’s a step up in my career and I think this is the perfect place for me to continue developing,” revealed the 25-year-old. “It’s time for me to win some titles.

“It was an easy decision for me to make when I heard the club were interested in signing me.

“My family and close friends know Chelsea is the club I have dreamed about playing for so I’m really excited about the challenge and I’m looking forward to working with my new team-mates.”

The Blues have also been linked with re-signing Brazil defender David Luiz, whom they sold to Paris St Germain for £50million prior to the 2014 World Cup, ahead of Wednesday’s closure of the transfer window.